Process of embossing sheet-metal



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UNITED STATES PATENT OFFICE.

JAMES llTI'lIlE, OF BROOKLYN, NEV YORK.

PROCESS OF EMBOSSING SHEET-METAL.

SPECIFICATION forming part of Letters Patent N o. 511,392, datedDecember 26, 1893. Application filed March 23, 1892. Renewed May 29,1893. Serial No. 475,978. (No specimens.)

To all whom it may concern:

Be it known that I, JAMES WHITE,a citizen of the United States,residingat Brooklyn, Kings county, New York, have invented certain new anduseful Improvements in Processes of Embossing Sheet Metal, fullydescribed and represented in the following specification and theaccompanying drawings, forming a part of the same.

The object of this invention is to facilitate the production of embossedfigures in high relief upon sheet metal by stamping, pressing or drawingthe same in suitable dies, and the invention consists in a new process,to effect this object.

The method or process consists in rst crimping the sheet metal toproduce a nely corrugated structure, and secondly, pressing the metalbetween thel required tools to produce the raised or embossed designthereon. The crimping or corrugatingof the sheet metal disposes thesubstance of the metal in alternate ridges and hollows, and suchdisposition prepares the metal in a peculiar manner to yield and stretchmost favorably when it is subjected to the embossing tools. The crimpingproduces this eect, because it permits the metal, when it is pressedtransverse to the corrugations, to atten Vout between the ribs, and tothus furnish the required material without any extension of the bers.When pressed in a direction parallel with the corrugations the bers ofthe metal are stretched much less than in a fiat sheet, because there ismore material in a corrugated sheet than in a iiat sheet of the samesize, and the eXtension produced in embossing such sheet is secured withless separation of the bers.

By this invention ornaments in much higher relief may be producedwithout injury to the metal than can be produced from a plain flat sheetof the same thickness.

The invention will be understood by reference to the annexed drawings,in which- Figure 1 is a cross section of a at sheet with a hemisphereembossed thereon, with the embossing dies upon opposite sides of thesheet. Fig. 2 is a plan of the same sheet.

Fig. 3 is a plan, and Fig. 4 a longitudinal section of a strip withthree similar ornaments embossed thereon.

Figs. l and 2 are drawn to illustrate the flattening out of the metalbetween the corrugated ridges in the act of embossing.

A is a flat sheet with hemisphere B- embossed thereon.

G, G', are the embossing dies.

Thesheet is corrugated with alternate ridges c and hollows d, and thesection in Fig.` 1 shows the effect of the dies where the hemisphere is'pressed, in iiattening and stretching the ribs apart and diminishing thedepth of the hollows, the metal thus yielding freely to the operation ofthe tools without any extension whatever of its bers transverse to thecorrugations. The attened ribs are also shown by the curved lines c inFig. 2. In the other direction it is obvious that the metal would bestretched in some degree, but that the extension of the bers would bevery much less than in a flat sheet subjected to the same tools; becausethere would be much more substance in the metal to be extended, andbecause the tension lengthwise of the corrugations would also operate toatten the ridges and raise the bottoms of the hollows, the same as thetension in a transverse direction.

The eect in embossing the sheet metal is precisely the same whatever bethe nature of the ornament, the substance of the metal upon a given areaof the sheet being much greater than in a flat sheet of the same area,and the disposition of the corrugations furnishing a greater amount ofmaterial for the extension demanded in the embossing operation.

Sheet metal of N o. 26* gage may be crimped with ve or six ridges to theinch, and then readily embossed in high relief. My improvement istherefore especially valuable in the production of architecturalornaments from zinc, copper, and galvanizedl iron; which ornaments arecommonly painted in imitation of stone, and present a much closerresemblance to such material when the surface isroughened by thecrimping operation.

Heretofore, it has been common, when architectural ornaments in highrelief were required, to stamp the same of annealed zinc;

which requires the expense of an annealing oven, and then secure themupon flat sheets 5 of galvanized iron.

It is immaterial to my present invention what kind of tools be employedto produce the embossed design upon the crimped sheet metal.

Figs. 3 and 4 show the invention applied to an oblong plate of metaladapted to ornament a panel, frieze, or cornice, the sheet A beingcrimped transversely and three similar ornaments E in high reliefembossed upon the I5 samez which could not be done with galvanmy hand inthe presence of two subscribing witnesses.

J AMES WHITE. lVitnesses:

ANsoN 0. KITTREDGE, T. S. CRANE.

